Ron Dubreuil, associate professor of biological sciences at the University of Illinois at Chicago, reports the finding in the Oct. 23 issue of the Journal of Cell Biology.
Spectrin was first discovered in red blood cells, where it forms a protein scaffold under the cell's membrane. It was named for its ability to maintain the shape of cell "ghosts," which have been emptied of their contents. Ankyrin serves as the mortar that attaches spectrin to the red blood cell membrane.
Dubreuil and his UIC co-workers have spent a decade looking at different types of cells -- mostly epithelial -- trying to learn what cues tell spectrin where to assemble in cells. They use the fruit fly as their test animal because its genetic makeup has many striking similarities to humans.
"In our study, we showed spectrin doesn't have to bind to ankyrin to do its job," said Dubreuil. "This hints at a complexity we never had any idea about in trying to understand how these molecules work."
Dubreuil and his colleagues initially assumed that ankyrin was the key to targeting spectrin in all cells. But research in many laboratories had failed to find a cue for targeting that acted through ankyrin, so Dubreuil reworked his hypothesis.
"We decided to throw out our assumptions and start fresh," he said.
A laboratory fly was genetically engineered so that spectrin could no longer bind to ankyrin -- which, Dubreuil assumed, meant that spectrin should no longer attach to the membrane.
"We thought that was going to kill the function of the protein," he said, "but it didn't affect the ability of the protein to reach its destination at all. The molecule targeted correctly to the cell membrane." In fact, the genetically engineered flies often survived to adulthood, while mutants that lacked spectrin altogether died very early in development.
Meanwhile, Dubreuil discovered that another region of spectrin, called the PH domain, unexpectedly played an critical role. Removing the PH domain left spectrin unable to bind to the membrane in certain cells, and those flies died.
Dubreuil's research seeks to clarify how these proteins function in different cells. The hope is that researchers may one day create therapeutic molecules to compensate for genetic lesions in diseases such as hereditary anemia, Duchenne muscular dystrophy, cardiac arrhythmia and the degenerative brain disease spinocerebellar ataxia 5.
"As we learn more about mutations involving spectrin and their relationships to human diseases, we're going to have more and more questions about how these mutations affect specific functions of the molecule," he said.
Paul Francuch | EurekAlert!
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy